Why are Spurs playing on a Sunday?

It is a 3PM game which means it isn't because of Sky's Super Sunday, surely there is another reason? Both of London's bigger clubs played today.

So, why

5 They played in the Europa League and couldn't beat Panathanikos
4 They played in the Europa League and couldn't beat Panathanikos
3 They played in the Europa League and couldn't beat Panathanikos
2 They played in the Europa League and couldn't beat Panathanikos
1 They played in the Europa League and couldn't beat Panathanikos

Perhaps sandy and co. could shed some light on the situation, because surely London's self-proclaimed biggest club would at least be playing in a televised game or Saturday match?

In a way, this is similar to Chronic's article about us diving except there is an element of truth to this article